This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Objective: To understand the neural circuits and molecular mechanisms underlying the adolescent vulnerability to develop stress-induced psychopathology (anxiety and depression). Using microPET images, groups were defined based on high, middle, and low amygdala reactivity during a behavioral challenge. These subjects have been further characterized behaviorally and physiologically both prior to and following relocation stress. These data will be used to define the parameters that engender vulnerability to psychopathology. This research used WNPRC Animal Services, surgery, pathology, operational services, and library and information services.